You Can't Spell WebRTC Without RCE – Part 1

The blog post by Ian Dupont discusses the vulnerabilities associated with the Signal messaging app, particularly focusing on its use of WebRTC for real-time communication. As secure messaging apps gain popularity, the need for thorough research into their security becomes critical, especially given past exploits like Pegasus spyware. The series aims to simplify the complex task of researching messaging apps and mobile exploitation, starting with an investigation into WebRTC, which is integral to many messaging applications.

The first part of the series outlines the structure of WebRTC and its protocols, including RTP and RTCP, which handle audio and video data transmission. Signal uses a public fork of WebRTC, known as RingRTC, which has specific modifications for its implementation. The author emphasizes the importance of understanding these protocols to identify potential vulnerabilities.

The post details the process of injecting synthetic vulnerabilities into Signal's WebRTC implementation, aiming to demonstrate how these vulnerabilities can be exploited. The author plans to remove certain mitigations that prevent premature parsing of RTP packets, thereby creating a 0-click attack surface. The research will also cover the setup of a local research environment and the use of tools like Frida for mobile exploitation.

Overall, the series intends to provide foundational knowledge for security researchers interested in mobile app vulnerabilities, particularly within the context of Signal and WebRTC, while also offering practical insights into the exploitation process.